And there I was walking out of the general store in Winterhold when I spotted someone running down the street at full tilt. Finally caught up to her just beneath the bridge crossing over to the college, and to my surprise it's a vampire fledgling. I kept clicking on her but she said nothing, nor was she hostile to me. She just kept running. Finally, after getting further away from Winterhold, clicking on her yielded a "Don't speak to me, meat!" response (at which point I immediately regretted not naming my character "meat").
Out of curiosity, I kept following her just to see where she was headed. She eventually ducked inside Septimus Sigmus's Outpost at which she point she promptly disappeared.
So, I reloaded and this time I killed her which netted me an assault on the crime sheet. She wasn't carrying anything out of the ordinary. Just the usual vampire crap. I was almost expecting her to be carrying a note because she was moving like one of those Imperial/Stormcloak couriers you run into every now and again. Very strange. Especially so, given my level. Anyone else have a similar experience?